Reusable Push-Activated Intraosseous Access Device

ABSTRACT

Disclosed herein are push activated intraosseous (IO) access devices, and methods thereof. Embodiments include replaceable and rechargeable or non-rechargeable battery packs, or spring driven devices. Intraosseous access devices often require training to ensure correct placement of the access device. Users must coordinate the opposing actions of pulling proximally on a trigger, while applying sufficient distal drive force to penetrate the bone. Devices disclosed herein include an intuitive operation with a unidirectional activation and drive force application. Further the trigger is both activated and deactivated automatically to prevent premature activation and prevent “backwalling”. The device includes various indicators to further guide a user in placing the device correctly, with little or no training. Devices further include replaceable battery packs to ensure a full charge is available when the device is used, and to provide a multi-use device that requires less storage.

PRIORITY

This application claims the benefit of priority to U.S. Provisional Application No. 63/013,371, filed Apr. 21, 2020, which is incorporated by reference in its entirety into this application.

SUMMARY

Intraosseous access devices often require training to ensure correct placement of the access device. Users must coordinate the opposing actions of pulling proximally on a trigger, while applying sufficient distal driving force to penetrate the bone. Too little distal driving force results in osteonecrosis, where the needle tip rotates against the bone causing friction burns, instead of cutting into the bone as intended. Too much distal driving force can result in “back walling” where a needle penetrates a far wall of the bone. Further complications can arise when accessing bones of different sizes and density depending on the age and health of the patient. Moreover, IO access devices are often used in emergency situations where delays can be critical and fully trained users may not always be available.

Embodiments disclosed herein are directed to push activated intraosseous (IO) access devices, and methods thereof. Push activated IO devices provide an intuitive operation with a unidirectional activation and drive force application. Further the device is both activated and deactivated automatically to prevent premature activation, guide a correct amount of distal driving force, and prevent “backwalling.” The device includes various indicators to further guide a user, who may have little or no training, in placing the device correctly. IO access devices disclosed herein further include replaceable battery packs, which may be either rechargeable or non-rechargeable, to ensure a full charge is available when the device is used, as well as providing a multi-use device that requires less storage space.

Disclosed herein is an intraosseous access device including, a housing, a trigger, and a drive train assembly, a portion of the drive train assembly slidably engaged with the housing, and configured to transition between a distal position, and a proximal position that actuates the trigger.

In some embodiments, the portion of the drive train assembly slidably engaged with the housing includes one of an electric motor, a gear assembly, a coupling structure, or an access assembly. The trigger is configured to connect a power supply with the drive train assembly when the trigger is actuated. The power supply is a battery pack disposed within the housing and configured to be removable and replaceable therefrom and wherein the battery pack is rechargeable or non-rechargeable. In some embodiments, the intraosseous access device further includes one of a force transducer, a variable speed sensor, a battery charge indicator, a timed stop sensor, or a trigger lock. The variable speed transducer is configured to modify a speed of the electric motor according to the amount of distal driving force applied to the intraosseous access device. The timed stop sensor is configured to stop the electric motor after a predetermined amount of time has elapsed. The trigger lock is transitionable between a locked position and an unlocked position, the trigger lock inhibiting the portion of the drive train assembly from transitioning to the proximal position when in the locked position.

In some embodiments, the intraosseous access device further includes a biasing member configured to bias the portion of the drive train assembly towards the distal position. A first force required to deform the biasing member and transition the portion of the drive train assembly from the distal position to the proximal position is greater than a second force required for a needle of an access assembly to penetrate a skin surface and less than a third force required for the needle to penetrate a bone cortex. In some embodiments, the intraosseous access device further includes a tensioning nut configured to adjust a tension of the biasing member. In some embodiments, the intraosseous access device further includes a force indicator configured to indicate an amount of force exerted on the biasing member. The force indicator includes one of a mechanical slider, a rotational dial, a series of graduated markings, or a series of LED lights.

Also disclosed is a method of placing an intraosseous access assembly including, providing an intraosseous access device having a driver, a drive train assembly, a portion of the drive train assembly transitionable between a first position and a second position, and an access assembly coupled to the drive train and including a needle, providing a first force to urge the access device distally until a tip of the needle penetrates a skin surface and contacts a bone cortex, providing a second force to urge the access device distally and transition the portion of the drive train assembly from a first position to a second position, rotating the access assembly, and drilling the needle through a bone cortex.

In some embodiments, the drive train includes one of a power source, an electronic control board, an electric motor, a gear assembly, or a coupling interface. The power source further includes a replaceable rechargeable or non-rechargeable battery pack. The drive train includes one of a drive spring, a drive spindle, a locking flange, or a coupling interface. In some embodiments, the method further includes an activation biasing member configured to bias the portion of the drive train assembly towards the first position, and wherein a force required to deform the activation biasing member is greater than the first force and less than second force. In some embodiments, the method further includes a tensioning nut configured to adjust a tension of the activation biasing member. In some embodiments, the method further includes a time out sensor configured to cease rotating the access assembly after a predetermined amount of time has elapsed.

Also disclosed is an access device including a driver housing, a drive spindle configured to rotate axially within the driver housing and configured to transition between a locked position and an unlocked position, a drive spring configured to rotate the drive spindle, and an access assembly coupled to the drive spindle.

In some embodiments, the access device further includes an activation biasing member configured bias the drive spindle to the locked position. A first force required to deform the activation biasing member and transition the drive spindle from the distal position to the proximal position is greater than a second force required for a needle of the access assembly to penetrate a skin surface and less than a third force required for the needle to penetrate a bone cortex. The activation biasing member is a compression spring and the first force is between 2 lbs and 4 lbs of force. In some embodiments, the access device further includes a tensioning nut threadably engaged with the driver housing, and configured to modify an amount of force required to deform the activation biasing member. The drive spindle further includes a locking flange configured to engage the driver housing and inhibit axial rotation when the drive spindle is in the locked position. The locking flange engages the driver housing with one of a plurality of ratchet teeth, a lug and detent, a frangible bridge, or a locking lever. The drive spring includes one of a torsion spring or a flat spring.

DRAWINGS

A more particular description of the present disclosure will be rendered by reference to specific embodiments thereof that are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. Example embodiments of the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

FIG. 1 illustrates an exploded view of an embodiment of an intraosseous access system, wherein an access assembly subset of the system is depicted slightly enlarged and in elevation, and an automated driver component is depicted in perspective, in accordance with embodiments disclosed herein;

FIG. 2A illustrates a side view of an intraosseous access system, in accordance with embodiments disclosed herein;

FIG. 2B illustrates a cross-sectional view of an intraosseous access system with an access assembly in a first, distal position, in accordance with embodiments disclosed herein;

FIG. 2C illustrates a cross-sectional view of an intraosseous access system with an access assembly in a second, proximal position, in accordance with embodiments disclosed herein;

FIG. 2D illustrates close up detail of the device of FIG. 2A, in accordance with embodiments disclosed herein;

FIG. 3 illustrates a cross-sectional view of an intraosseous access system, in accordance with embodiments disclosed herein;

FIG. 4 illustrates a cross-sectional view of a spring-driven intraosseous access device, in accordance with embodiments disclosed herein;

FIGS. 5A-5H illustrate close-up details of a spring-driven intraosseous access device, in accordance with embodiments disclosed herein; and

FIG. 6A illustrates a cross-sectional view of a spring-driven intraosseous access device, in accordance with embodiments disclosed herein.

FIG. 6B illustrates a schematic view of the spring drive of the spring-driven intraosseous access device for FIG. 6A, in accordance with embodiments disclosed herein.

FIGS. 6C-6D illustrate cross-sectional views of a spring-driven intraosseous access device, in accordance with embodiments disclosed herein.

FIGS. 6E-6F illustrate cross-sectional views of a geared, spring-driven intraosseous access device, in accordance with embodiments disclosed herein.

DESCRIPTION

Before some particular embodiments are disclosed in greater detail, it should be understood that the particular embodiments disclosed herein do not limit the scope of the concepts provided herein. It should also be understood that a particular embodiment disclosed herein can have features that can be readily separated from the particular embodiment and optionally combined with or substituted for features of any of a number of other embodiments disclosed herein.

Regarding terms used herein, it should also be understood the terms are for the purpose of describing some particular embodiments, and the terms do not limit the scope of the concepts provided herein. Ordinal numbers (e.g., first, second, third, etc.) are generally used to distinguish or identify different features or steps in a group of features or steps, and do not supply a serial or numerical limitation. For example, “first,” “second,” and “third” features or steps need not necessarily appear in that order, and the particular embodiments including such features or steps need not necessarily be limited to the three features or steps. Labels such as “left,” “right,” “top,” “bottom,” “front,” “back,” and the like are used for convenience and are not intended to imply, for example, any particular fixed location, orientation, or direction. Instead, such labels are used to reflect, for example, relative location, orientation, or directions. Singular forms of “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise.

With respect to “proximal,” a “proximal portion” or a “proximal end portion” of, for example, a needle disclosed herein includes a portion of the needle intended to be near a clinician when the needle is used on a patient. Likewise, a “proximal length” of, for example, the needle includes a length of the needle intended to be near the clinician when the needle is used on the patient. A “proximal end” of, for example, the needle includes an end of the needle intended to be near the clinician when the needle is used on the patient. The proximal portion, the proximal end portion, or the proximal length of the needle can include the proximal end of the needle; however, the proximal portion, the proximal end portion, or the proximal length of the needle need not include the proximal end of the needle. That is, unless context suggests otherwise, the proximal portion, the proximal end portion, or the proximal length of the needle is not a terminal portion or terminal length of the needle.

With respect to “distal,” a “distal portion” or a “distal end portion” of, for example, a needle disclosed herein includes a portion of the needle intended to be near or in a patient when the needle is used on the patient. Likewise, a “distal length” of, for example, the needle includes a length of the needle intended to be near or in the patient when the needle is used on the patient. A “distal end” of, for example, the needle includes an end of the needle intended to be near or in the patient when the needle is used on the patient. The distal portion, the distal end portion, or the distal length of the needle can include the distal end of the needle; however, the distal portion, the distal end portion, or the distal length of the needle need not include the distal end of the needle. That is, unless context suggests otherwise, the distal portion, the distal end portion, or the distal length of the needle is not a terminal portion or terminal length of the needle.

As shown in FIG. 1, and to assist in the description of embodiments described herein, a longitudinal axis extends substantially parallel to an axial length of a needle 204 extending from the driver 101. A lateral axis extends normal to the longitudinal axis, and a transverse axis extends normal to both the longitudinal and lateral axes.

As used herein, the term “spring” is considered to include any type of spring or biasing member that may store potential mechanical energy. Exemplary biasing members can include compression springs, extension springs, torsion springs, constant force springs, flat spring, flexible members, rubber rings, rubber band, leaf spring, V-spring, cantilever spring, volute spring, Belleville spring, gas spring, gravity-propelled biasing members, combinations thereof and the like, and are considered to fall within the scope of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art.

The present disclosure relates generally to intraosseous (IO) access devices, systems, and methods thereof. FIG. 1 shows an exploded view of an exemplary intraosseous access system (“system”) 100, with some components thereof shown in elevation and another shown in perspective. In an embodiment, the intraosseous access system 100 can be used to penetrate skin and underlying hard bone (“bone cortex”) for intraosseous access, such as, for example to access the marrow of the bone and/or a vasculature of the patient via a pathway through an interior of the bone (“medullary cavity”).

In an embodiment, the system 100 includes a driver 101 and an access assembly 109. The driver 101 can be used to rotate the access assembly 109 and “drill” a needle 204 into the bone of a patient. In embodiments, the driver 101 can be automated or manual. As shown, the driver 101 is an automated driver 101. For example, the automated driver 101 can be a drill that achieves high rotational speeds. In an embodiment, the intraosseous access system 100 can further include an obturator assembly 102, a shield 105, and a needle assembly 202, which may be referred to, collectively, as the access assembly 109. The needle assembly 202 can include an access needle (“needle”) 204 supported by a needle hub 203, as described in more detail herein. In an embodiment, the obturator assembly 102 includes an obturator 104. However, in some embodiments, the obturator 104 may be replaced with a different elongated medical instrument. As used herein, the term “elongated medical instrument” is a broad term used in its ordinary sense that includes, for example, such devices as needles, cannulas, trocars, obturators, stylets, and the like. Accordingly, the obturator assembly 102 may be referred to more generally as an elongated medical instrument assembly. In like manner, the obturator 104 may be referred to more generally as an elongated medical instrument.

In an embodiment, the obturator assembly 102 includes a coupling hub 103 that is attached to the obturator 104 in any suitable manner (e.g., one or more adhesives or overmolding). The coupling hub 103 can be configured to interface with the driver 101, as further discussed below. The coupling hub 103 may alternatively be referred to as an obturator hub 103 or, more generally, as an elongated instrument hub 103. In an embodiment, the shield 105 is configured to couple with the obturator 104 to prevent accidental needle stick injuries when the obturator is removed after placement of the needle 204.

In an embodiment, the needle assembly 202 includes a needle 204. However, in some embodiments, the needle 204 may be replaced with a different instrument, such as, for example, a cannula, a tube, or a sheath, and/or may be referred to by a different name, such as one or more of the foregoing examples. Accordingly, the needle assembly 202 may be referred to more generally as a cannula assembly or as a tube assembly. In like manner, the needle 204 may be referred to more generally as a cannula.

In an embodiment, the needle assembly 202 includes a needle hub 203 that is attached to the needle 204 in any suitable manner. The needle hub 203 can be configured to couple with the obturator hub 103 and may thereby be coupled with the driver 101, as further discussed below. The needle hub 203 may alternatively be referred to as a cannula hub 203. In an embodiment, a cap 107 may be provided to cover at least a distal portion of the needle 204 and the obturator 104 prior to use of the access assembly 109. For example, in an embodiment, a proximal end of the cap 107 can be coupled to the obturator hub 103.

With continued reference to FIG. 1, the driver 101 may take any suitable form. The driver 101 may include a handle 110 that may be gripped by a single hand of a user. In an embodiment, the driver 101 further includes a coupling interface 112, which is formed as a socket 113 that defines a cavity 114. The coupling interface 112 can be configured to couple with the obturator hub 103. In an embodiment, the socket 113 includes sidewalls that substantially define a hexagonal cavity into which a hexagonal protrusion of the obturator hub 103 can be received. Other suitable connection interfaces are also contemplated.

The driver 101 can include an energy source 115 of any suitable variety that is configured to energize the rotational movement of the coupling interface 112. For example, in some embodiments, the energy source 115 may comprise one or more batteries that provide electrical power for the driver 101. In some embodiments, the energy source 115 can comprise one or more springs (e.g., a coiled spring, flat spring, or the like) or other biasing member that may store potential mechanical energy that may be released upon actuation of the driver 101.

The energy source 115 may be coupled with the coupling interface 112 in any suitable manner. For example, in an embodiment, the driver 101 includes an electrical, mechanical, or electromechanical coupling 116 to a gear assembly 117. In some embodiments, the coupling 116 may include an electrical motor that generates mechanical movement from electrical energy provided by an electrical energy source 115. In other embodiments, the coupling 116 may include a mechanical linkage to the gear assembly 117. The driver 101 can include a mechanical coupling of any suitable variety to couple the gear assembly 117 with the coupling interface 112. In other embodiments, the gear assembly 117 may be omitted.

Further details and embodiments of the intraosseous access system 100 can be found in WO 2018/075694, WO 2018/165334, WO 2018/165339, and US 2018/0116693, each of which is incorporated by reference in its entirety into this application.

FIG. 2A shows an embodiment of an intraosseous access device 100, including a driver 101 that includes a replaceable battery pack energy source (“battery pack”) 115. In an embodiment the battery pack 115 is removable and replaceable with similar battery packs. In an embodiment, the battery pack 115 can either be rechargeable or non-rechargeable. Advantageously, this allows a user of the system 100 to ensure there is sufficient power when the system is deployed in a placement event. Further, during a placement event, should the power be depleted from the first battery pack, a user can replace the first battery pack with a second, fully charged battery pack and continue the access procedure without having to wait for the first battery pack to be charged. As discussed herein, intraosseous access devices are often used in emergency situations and are therefore kept in storage for extended periods of time before being rapidly deployed in a placement event. The replaceable battery pack 115 mitigates a user's concerns about there being sufficient charge during a placement event.

In an embodiment, the driver 101 includes a battery charge indicator 170. In an embodiment, the battery charge indicator 170 is disposed on the battery pack 115. The battery charge indicator 170 can include one or more LED lights, icons, or the like, that can turn on or off, change color, or combinations thereof, to indicate a level of charge of the battery pack 115. In an embodiment, the system 100 includes a charge indicator button 171 that a user can actuate to activate the battery charge indicator 170 and determine a charge level for the battery pack 115. Advantageously, the driver 101 and one or more replacement battery packs 115 can provide sufficient power for multiple uses while requiring less storage space compared with multiple, single-use, devices. Further, the overall costs are reduced by requiring only a replacement battery pack rather than requiring multiple, single-use access systems.

As shown in FIGS. 2B-2C, in an embodiment, the driver 101 includes a pressure activated trigger 111. The trigger 111 can be activated by an axial pressure on the access assembly 109. In an embodiment, a longitudinal pressure can depress the access assembly 109 in a proximal direction and activate the trigger 111, which activates the motor 116 and causes the access assembly 109 to rotate.

As used herein the battery pack 115 and any associated electronic control boards 115A, motor 116, associated gear assemblies 117, coupling structures 112, access assembly 109, or combinations thereof, can be collectively termed a drive train assembly (“drive train”) 118. In an embodiment, the drive train 118 or a portion thereof, can be slidably engaged within a housing 108 of the driver 101. For example, as shown in FIGS. 2B-2C, a portion of the drive train 118, including the motor 116, coupling structures 112, and access assembly 109, can be slidably engaged along a longitudinal axis between a first, distal position (FIG. 2B) and a second, proximal position (FIG. 2C).

It will be appreciated, however, that any combination of components of the drive train 118 can be slidably engaged with the housing 108 with the remaining components of the drive train 118 remaining stationary. For example, in an embodiment, the portion of the drive train 118 slidably engaged with the housing 108 can include only the access assembly 109 with the remaining components remaining stationary. In an embodiment, all components of the drive train 118 can be slidably engaged with the housing 108. In an embodiment, a component of the drive train 118 can be further sub-divided with a first portion remaining stationary and second portion slidably engaged with the housing 108. For example, the coupling structures 112 can be made of a first piece slidably engaged with a second piece. As such, the portion of the drive train 118 that is slidably engaged with the housing 108 can include the access assembly 109 and a second piece of the coupling structures 112. These and other combinations of drive train assembly 118 are considered to fall within the scope of the present invention.

In an embodiment, a biasing member, for example an activation spring 190, can bias the slidable drive train 118, or portion thereof that is slidably engaged with the housing 108, towards a distal position. In an embodiment, a biasing member (e.g. a spring) can be disposed between a first portion and a second portion of the driver train 118, for example between the second piece of coupling structure 112 and the access assembly 109, to bias a portion of the drive train 118 towards a distal position. These and similar combinations of slidable drive train 118 are considered to fall within the scope of the present invention.

In an embodiment, the activation spring 190 can be a compression spring disposed within the driver 101, between the portion of the slidable drive train 118 and a distal end of the driver housing 108. However, as discussed herein, it will be appreciated that various other forms of biasing members are also contemplated, including compliant rubber discs, flexible metal tabs, or similar structures configured to bias the drive train 118 towards a distal position. In an embodiment, the driver 101 further includes a tensioning nut 130. In an embodiment, rotating the tensioning nut 130 can adjust the tension on the activation spring 190, and can modify the amount of force required to compress the activation spring 190 and activate the device, as discussed in more detail herein.

In an embodiment, a force required to compress the activation spring 190 can be between 2 lbs and 4 lbs, although greater or lesser forces are also contemplated. As shown in FIG. 2B, in an embodiment, a force required for the needle 204 to penetrate the skin tissues 70 can be less than a force required to compress activation spring 190. As such the activation spring 190 can maintain the drive train 118 in a proximal position as the needle penetrates the skin tissues 70. In an embodiment, a force required for the needle 204 to penetrate the bone cortex 80 can be greater than a force required to compress activation spring 190. As such, when the needle tip 246 contacts the bone cortex 80, a user can apply additional distal driving force to compress the activation spring 190 and transition the drive train 118 from the distal position (FIG. 2B) to the proximal position (FIG. 2C).

As shown in FIG. 2C, in the proximal position, the drive train 118 contacts the trigger 111, which activates the motor 116 and rotates the access assembly 109. The needle tip 246 then drills through the bone cortex 80 and accesses the medullary cavity 90. The density of the tissue within the medullary cavity 90 is less than the density of the bone cortex 80. As such, a force required for the needle 204 to penetrate the tissues of the medullary cavity 90 can be less than a force required to compress activation spring 190. When the needle tip 246 enters the medullary cavity 90, the force of the activation spring 190 transitions the drive train 118 back to the distal position. This disengages the trigger 111, stops the motor 116 and automatically stops any rotation of the access assembly 109.

In an embodiment, the driver 101 can further include a tensioning nut 130, which is configured to rotate and move a spring support 194 along a longitudinal axis. This can adjust the amount force required to transition the drive train 118 from the distal position to the proximal position. As such, the tension of the activation spring 190 can be adjusted depending on various factors including age of the patient, health condition of the patient, the density of the bone cortex 80, the density of the tissue within the medullary cavity 90, combinations thereof, or the like.

In an exemplary method of use, an intraosseous access system 100 is provided including a driver 101, an access assembly 109, and a replaceable battery 115, as described herein. In an embodiment, the access assembly 109 and/or the replaceable battery 115 are provided pre-loaded in the driver 101. In an embodiment the access assembly 109 and/or the replaceable battery 115 are provided separately and the user can load the access assembly 109 and/or the replaceable battery 115 to the driver 101 prior to use. The user can check a charge level of the battery 115 using battery level indicator 170. If necessary the user can replace the battery 115 with a fully charged battery 115. In an embodiment, the system 100 can further include a cap 107 to protect the needle 204 of the access assembly 109.

The user can position a tip 246 of the needle 204 at the insertion site and apply a distal driving force to urge the driver 101 in a distal direction. As described herein, the activation spring 190 is configured to maintain the driver train 118 in a distal position as the needle 204 is urged through the skin surface tissues 70. The distal tip 246 of the needle 204 then contacts the hard bone cortex 80 which inhibits further distal advancement. The user continues to urge the driver 101 distally with sufficient force to overcome the force of the activation spring 190. This causes the drive train 118 to slide proximally, relative to the driver 101, and activate the trigger 111. The trigger 111 activates the motor 116 which causes the access assembly 109 to rotate and drill the needle 204 through the bone cortex 80. When the needle tip 246 penetrates through the bone cortex 80 and into the medullary cavity 90, the activation spring 190 can transition the drive train 118 back to the distal position since the force of the activation spring is greater than a force required to penetrate the needle 204 through tissues of the medullary cavity 90. In the distal position, the trigger 111 is disengaged, which disengages the motor 116 and ceases rotation of the access assembly 109.

Advantageously, the system 100 provides an intuitive function that only requires a single directional force to be applied to start the placement event, i.e. start drilling, compared with pulling a “pistol-style” trigger in a proximal direction while applying a driving force in a distal direction. Further, the activation spring 190 can be configured to deform and activate the device 100 automatically when the correct level of distal driving force is applied. A user can progressively increase the amount of distal driving force until the activation spring 190 compresses and activates the system 100, guiding the user towards a correct level of distal driving force.

Further still, the activation spring 190 can be configured to deactivate the device 100 automatically either when the user removes the distal driving force or when the needle 204 accesses medullary cavity 90. The automatic deactivation can indicate to a user of successful placement. This is of particular importance to prevent “back walling” which can lead to various complications. Further, the automatic deactivation of the device can act as a safety feature, deactivating the device if the device is removed from the insertion site. In an embodiment, the drive train 118 can also be configured to apply the correct torque and rotational speed for fast and effective access.

In an embodiment, the system 100 can be configured to modify the amount of torque and/or rotational speed based on the amount distal driving force applied. As such the system 100 can be configured to guide a user to deliver the correct balance of distal driving force, torque, and rotational speed for an intuitive, fast and efficient IO access placement. A user thereby requires little or no training to use the system 100. This is of particular importance intraosseous access devices are often used within emergency situations where speed of placement is important, and users may not necessarily have had any prior training.

In an embodiment, the driver 101 can be configured in a variety of compact or ergonomic shapes. For example, user-actuated triggers, i.e. devices that are selective actuated by a user, can be limited to pistol-grip style configurations in order to position the trigger in an accessible position. Automatic, pressure-activated triggers are not reliant on such configurations and can allow for more compact or ergonomic configurations of the system 100. For example, as shown in FIG. 3, a cylindrical driver 101A is provided that defines a substantially tubular shape extending along a longitudinal axis. Such designs can provide more compact drivers 101 than pistol-grip style drivers leading to greater efficiencies in the storage and transport of the devices. These and other ergonomic or compact designs are also contemplated to fall within the scope of the present invention.

In an embodiment, the driver 101 includes a force sensor (not shown), in addition to the activation spring 190, that is configured to automatically stop the driver 101 once the bone cortex 80 has been penetrated. In an embodiment the force sensor is a pressure transducer that detects an axial force applied to the needle tip 246. The force sensor can be configured to detect a presence or absence of axial force applied to the needle tip 246. The system 100 can then determine when the needle tip 246 has penetrated the bone cortex 80 and entered the medullary space 90, and can deactivate the motor 116 to prevent further drilling. Advantageously, the force sensor provides an additional safeguard to prevent back walling. Further, the force sensor can allow a user to selectively activate or deactivate the driver 101 during the placement event, by applying or removing a distal driving force.

In an embodiment, the driver 101 includes a variable speed sensor configured to adjust the speed of the motor 116 proportionally to the amount of distal driving force that is applied to the driver 101. For example, the variable speed sensor is configured to detect the amount of force applied to the driver 101, or amount of deformation applied to the activation spring 190, or the like. The variable speed sensor then increases the speed of the motor proportionally to the amount of force applied or deformation detected. Advantageously, the variable speed sensor balances the correct rotational speed with the amount of distal driving force applied to provide efficient intraosseous placement. This prevents osteonecrosis or back walling, as discussed herein. Advantageously, on activation, the driver 101 can be configured to “ramp up” the motor speed to prevent a sudden start to the activation, which can cause the needle tip 246 to travel away from the selected insertion site leading to misplacement of the access device. Further, the sudden start to the activation can startle the user and also lead to misplacement of the access device.

In an embodiment, the driver 101 includes a timed stop sensor. The timed stop sensor provides an automatic stop after a set amount of time has elapsed since the device was activated. In an embodiment, the timed stop sensor deactivates the motor between 3 seconds and 59 seconds after the motor has been activated. Advantageously, the timed stop sensor provides a safeguard against back walling, by deactivating the motor after a predetermined amount of time has elapsed e.g. 2-3 seconds, or an amount of time required to drill through the bone cortex 80. Further, the timed stop sensor also prevents the battery from being depleted accidentally, for example, during an accidental activation event during storage or transport.

In an embodiment, the driver 101 includes a trigger lock. The trigger lock can include a slide switch, electronic switch, or the like, configured to prevent premature activation of the trigger 111. For example, the trigger lock can be a slide switch configured to inhibit the drive train 118 from transitioning from the distal position to the activated, proximal position. During use, the user can release the trigger lock switch prior to starting the access event. Advantageously, the trigger lock can prevent accidental activation of the driver 101 prior to use, e.g. during transport or storage.

As shown in FIGS. 2A, 2D, in an embodiment, the driver 101 includes a distal driving force indicator 310. The force indicator 310 can include a series of LED lights, a mechanical slider, a rotational dial, combinations thereof, or the like, and include graduated markings 314. The force indicator 310 can include a mechanical or electronic transducer that detects an amount of distal driving force applied to the driver 101 and indicate the amount force, relative to a correct amount of force, which needs to be applied. For example, FIG. 2D shows close up detail of a force indicator 310 that can be disposed on an outer surface of the driver 101. In an embodiment, the drive train 118 can be linked with a slider 312 disposed on an outer surface of the driver 101. As the user applies a distal driving force, the drive train 118 can slide proximally relative to the driver 101, as described herein. The slider 312, coupled with the drive train 118 can also slide proximally relative to the driver housing 108. A series of graduated markings 314 disposed on the driver housing 108, together with the slider 312, can indicate to a user if sufficient distal driving force is being applied, or too much force, or too little force. Advantageously, the force indicator 310 can further guide a user as to the correct operation of the system 100, even if the user has had little or no training. In an embodiment, the force indicator 310 includes a rotational dial that rotates about a series of graduated markings to indicate an amount of force applied. In an embodiment, the force indicator 310 includes one or more LED lights that turn on and off, and/or change color, to indicate an amount of force applied. These and similar configurations of mechanical or electronic force indicators are considered to fall within the scope of the present invention.

As shown in FIG. 4, in an embodiment, an intraosseous access system 200 generally includes a spring driven energy source 215, and a force actuation spring 290. The access system 200, includes a driver 201 having a driver housing 208 defining a substantially cylindrical shape, although other shaped housings 208 are also contemplated. The access system 200 further includes a spring driven energy source 215 and a drive spindle 220, disposed within the driver housing 208. The drive spindle 220 is configured to rotate about a longitudinal axis of the driver 201. The drive spindle 220 is further configured to slide along a longitudinal axis between a distal, locked position, and a proximal unlocked position, as described in more detail herein. The drive spindle 220 further includes a locking flange 222 that is configured to engage the driver housing 208 when the drive spindle 220 is in the distal, locked position, and disengage the driver housing 208 when the driver spindle 220 is in the proximal unlocked position, as described in more detail herein.

The spring driven energy source (“drive spring”) 215 can include a torsion spring configured to store rotational potential energy. However, it will be appreciated that other biasing members are also contemplated. The drive spring 215 can be coupled with both the driver housing 208 and the drive spindle 220 in a tensioned state. As such, when the locking flange 222 disengages the driver housing 208, allowing the drive spindle 220 to rotate freely, the drive spring 215 causes the drive spindle 220 to rotate about the longitudinal axis.

In an embodiment, the driver 201 further includes a coupling interface 212 disposed at a distal end of the drive spindle 220 and configured to engage an access assembly 109, as described herein. Rotation of the drive spindle 220 can cause the access assembly 109 to rotate and causes the needle 204 to drill through the bone cortex 80, and access the medullary cavity 90, as described herein. As used herein, the drive spring 215, drive spindle 220, locking flange 222, coupling interface 212, or combinations thereof can be collectively termed a drive train assembly.

In an embodiment, the driver housing 208 includes a tensioning nut 230 threadably engaged with the driver housing 208. Rotating the tensioning nut 230 about the longitudinal axis, can cause the nut 230 to move along the longitudinal axis relative to the driver housing 208. In an embodiment, the driver 201 includes a force activation spring 290, disposed annularly about the drive spindle 220, between the tensioning nut 230 and the coupling interface 212. In an embodiment, the activation spring 290 is a compression spring, configured to resist a compressive force before deforming. In an embodiment, the compressive force required to deform the spring is between 2-4 lbs of force, although greater or lesser forces are also contemplated. In an embodiment, rotating the tensioning nut 230 can modify the amount of compressive force required to deform the activation spring 290. In an embodiment, the activation spring 290 is configured to bias the drive spindle 220 towards the distal locked position. When a proximal force is applied to the needle tip 246, sufficient to compress the activation spring 290, the drive spindle 220 can move to the proximal unlocked position, activating the device.

In an embodiment, the coupling interface 212 is threadably engaged with drive spindle 220, such that rotating the coupling interface 212 about the longitudinal axis causes the coupling interface 212 to move longitudinally relative to the drive spindle 220. As such, rotating the coupling interface 212 can modify the tension of the activation spring 290 disposed between the coupling interface 212 and the driver housing 208 or tensioning nut 230.

In an embodiment, the locking flange 222 can include one or more locking features configured to allow the locking flange 222 to selectively engage or disengage the driver body 208. FIGS. 5A-5H show some exemplary embodiments of locking features. In an embodiment the flange 222 can include a first, flange locking feature, e.g. flange ratchet teeth 224, configured to selectively engage a second, driver locking feature, e.g. housing ratchet teeth 234, to selectively inhibit relative movement therebetween.

As shown in FIGS. 5A-5B, in an embodiment, the locking flange 222 includes a plurality of ratchet teeth 224 that are configured to engage a plurality of housing ratchet teeth 234 disposed on the housing 208, tensioning nut 230, or combinations thereof. The flange ratchet teeth 224 and housing ratchet teeth 234 are configured to engage to inhibit rotational movement of the drive spindle 222 about the longitudinal axis in a first direction, e.g. a clockwise direction, and configured to allow stepwise rotation in a second, opposite, direction, e.g. anti-clockwise direction. Advantageously, this allows the drive spring 215 to be tensioned by rotating the drive spindle 220 in the second direction. The system 200 maintains the tension by the engagement of the flange ratchet teeth 224 and housing ratchet teeth 234 to prevent rotation in the first direction. In an embodiment, when a proximal force is applied to the needle tip 246, which is sufficient to overcome the compression force of the activation spring 290, the spindle 220 and locking flange 222 move proximally and disengage the flange ratchet teeth 224 from the housing ratchet teeth 234 to allow free rotation of the spindle 220. The drive spring 215 then causes the drive spindle 220 to rotate as described herein.

As shown in FIGS. 5C-5D, in an embodiment, the drive spindle 220 includes one or more lugs 226 that engage one or more detents 236 disposed within the housing 208, tension nut 230, or combinations thereof. As shown in FIG. 5C, the lugs 226 engage the detents 236 and prevent rotational movement of the drive spindle 220. In an embodiment, when a proximal force is applied to the needle tip 246, which is sufficient to overcome the compression force of the activation spring 290, the spindle 220 and locking flange 222 move proximally and disengage lugs 226 from the detents 236 to allow free rotation of the spindle 220. The drive spring 215 then causes the drive spindle 220 to rotate as described herein.

As shown in FIGS. 5E-5F, in an embodiment, the locking flange 222 includes a frangible bridge 228 that is formed between the locking flange 222 and the housing 208, tension nut 230, or combinations thereof. The frangible bridge 228 can include a tear line, e.g. a score line, laser cut line, perforation, or the like, that is configured to break when a predetermined force is applied, allowing the locking flange 222 to separate from the housing body 208 or tension nut 230. For example, when a proximal force is applied to the needle tip 246, which is sufficient to overcome the force required for the breach line to separate, the frangible bridge 228 detaches from the housing 208/tension nut 230, allowing the spindle 220 and locking flange 222 move proximally and to allow free rotation of the spindle 220. The drive spring 215 then causes the drive spindle 220 to rotate as described herein. In an embodiment, the frangible bridge 228 can be used in place of the activation spring 290 to prevent proximal movement until sufficient proximal force is applied. In an embodiment, the frangible bridge 228 can be used in addition to the activation spring 290 to prevent proximal movement until sufficient proximal force is applied.

As shown in FIGS. 5G-5H, in an embodiment, the driver 201 includes a locking lever 240, configured to engage the locking flange 222, drive spindle 220, or combinations thereof to prevent the drive spindle 220 from rotating. In an embodiment, an outer surface of the locking flange 222 includes one or more locking teeth. The locking lever 240 engages the locking teeth and prevents the drive spindle 220 from rotating. In an embodiment, when a proximal force is applied to the needle tip 246, which is sufficient to overcome the compression force of the activation spring 290, the spindle 220 moves proximally. As shown in FIG. 5H, a portion of the locking lever 240 is actuated by the proximal movement of the drive spindle 220 and causes the locking lever 240 to pivot and disengage from the locking flange 222 to allow free rotation of the spindle 220. The drive spring 215 then causes the drive spindle 220 to rotate as described herein.

In an exemplary method of use a spring driven intraosseous access system 200 is provided, as described herein, including a coiled drive spring 215 and an activation spring 290. A user urges the driver 201 distally until a needle tip 246 penetrate a skin surface 70. To note, the resistance of the needle 204 penetrating the skin tissues 70 is less than a force required to deform the activation spring 290. As such the drive spindle 220 and access assembly 190 remains a distal, locked position. The needle tip 246 then contacts the bone cortex 80, a user can continue to urge the driver 201 distally with sufficient force to deform the activation spring 290 by pressing the access assembly 109 into the bone cortex 80. The access assembly 109 and driver spindle 220 slides proximally relative to the driver housing 208, compressing the activation spring 290 between the coupling interface 212 and the tensioning nut 230 portion of the driver housing 208. The locking flange 222, coupled to the driver spindle 220, disengages from the driver housing 208 allowing the driver spindle 220 to rotate. The drive spring 215 causes the driver spindle 220 and access assembly 109 to rotate, drilling the needle 204 into the bone cortex 80 and accessing the medullary cavity.

As shown in FIGS. 6A-6B, in an embodiment, an intraosseous access system 300 is provided including a flat drive spring 315. The access system 300, includes a driver 301 having a driver body 308, with a flat drive spring 315, a drive spindle 320, and a collector spindle 321, disposed therein.

In a tensioned state, the drive spring 215 is wrapped about the drive spindle 220. As the drive spring transitions between a tensioned state and an untensioned state, the flat spring unwinds from the drive spindle 320, causing the drive spindle to rotate, and is wound on to the collector spindle 321. FIG. 6B shows a plan view of the drive spindle 320, the collector spindle 321 and the flat drive spring 315 extending therebetween, including the associated direction of rotation for each of the drive spindle 320 and the collector spindle 321. Advantageously, the flat drive spring provides a more constant torque and more constant rotational speed as the spring transitions between a tensioned and an untensioned state.

In an embodiment, the drive spindle 320 and the collector spindle 321 remain in a longitudinally fixed position, relative to the drive body 208. In an embodiment, a coupling interface 312 is slidably engaged with the drive spindle 320 along a longitudinal axis. The coupling interface 312 is also coupled with the drive spindle 320 such that any rotational movement of the drive spindle 320 causes the coupling interface 312 and access assembly 109 to rotate.

In an embodiment, the driver 301 includes an activation spring 390, disposed within the drive spindle 320 and is biased to maintain the coupling interface 312 is a distal position. When a force is applied to a needle tip 246 in a proximal direction, which is sufficient to overcome the force of the activation spring 390, the activation spring 390 can deform and allow the coupling interface 312 to slide longitudinally. The coupling interface can further include a locking flange, as described herein. As the coupling interface 312 transitions from a distal position to a proximal position, the locking flange can disengage allowing the coupling interface 312 and drive spindle 320 to rotate. The coupling interface 312 and locking flange can include various ratchet teeth, lugs and detents, frangible bridges, locking levers, combinations thereof, or the like, as described herein, to selectabley inhibit rotation of the coupling interface 312 and drive spindle 320 assembly until activated.

In an embodiment, the driver 301 further includes a tensioning nut 330, which is threadably engaged with the driver housing 208. As such, rotating the tensioning nut 330 about the longitudinal axis can modify the tension of the activation spring 390 which can modify the amount of force required to move the access assembly 109 longitudinally and trigger the device 300.

In an exemplary method of use a spring driven intraosseous access system 300 is provided, as described herein, including a flat drive spring 315 and an activation spring 390. A user urges the driver 301 distally until a needle tip 346 penetrates a skin surface 70. To note, the resistance of the needle 304 penetrating the skin tissues 70 is less than a force required to deform the activation spring 390. As such the activation spring 390 maintains the coupling interface 312 and access assembly 190 in a distal, locked position. The needle tip 246 then contacts the bone cortex 80 where the resistance to needle penetration is greatly increased. A user can continue to urge the driver 301 distally with sufficient force to deform the activation spring 390 by pressing the access assembly 109 into the bone cortex 80. The access assembly 109 and coupling interface 312 slides proximally relative to the driver housing 308, compressing the activation spring 390 between the coupling interface 312 and the tensioning nut 330. The locking feature, which is configured to inhibit rotation of the coupling interface 312, disengages from the driver housing 308 allowing the coupling interface 312 and access assembly 109 to rotate, drilling the needle 304 into the bone cortex 80 and accessing the medullary cavity 90.

Advantageously, the drive springs disclosed herein, e.g. drive spring 215, 315, can maintain the stored energy of over an extended period of time without depleting. Further, these drive springs include an inherent time stop feature to prevent backwalling, as described herein. i.e. The drive spring 215 can be configured to provide sufficient rotations of the access assembly to drill through the bone cortex before reaching an untensioned state and ceasing further drilling. In an embodiment, the drive springs are configured to provide between 10-20 rotations to provide sufficient drilling to penetrate the bone cortex and access the medullary cavity without backwalling. It will be appreciated, however, that the drive springs can also be configured to provide fewer or greater numbers of rotations.

In an embodiment, as shown in FIGS. 6C-6D, the drive train can include a drive spindle 320, drive spring 315, collector spindle 321, and access assembly 109. The drive train can be slidably engaged relative to the housing 308 along a longitudinal axis, as described herein. The activation spring 390 can be disposed between the drive train, e.g. the drive spindle 320, and the housing 308 and can bias the drive train towards a distal position (FIG. 6C). In an embodiment, one of the drive spindle 320 or the collector spindle 321 can include a locking engagement feature, as described herein, configured to selectively inhibit rotation of the drive spindle 320. For example, as shown in FIG. 6C, the drive spindle can include a first set of ratchet teeth 324 disposed on the drive spindle 320 configured to engage a second set of ratchet teeth 334 disposed on the housing 308 in the distal position. As shown in FIG. 6D an axial force applied to the access assembly 109 can compress the activation spring 390, allowing the drive train to transition to the proximal position. This in turn can allow the first set of ratchet teeth 324 to disengage the second set of ratchet teeth 334 and allow the drive spindle 320 to rotate, as described herein.

In an embodiment, as shown in FIGS. 6E-6F, the drive train can include the drive spindle 320, drive spring 315, collector spindle 321, and access assembly 109, and can further include a gear mechanism 317. The gear mechanism 317 can either be “geared up” or “geared down” to modify one of the speed or torque of the access assembly 109 relative to the rotation speed of the drive spindle 320. The gear mechanism 317 can include spur gears, planetary gears, helical gears, bevel gears, miter gears, worm gears, screw gears, combinations thereof, or the like.

In an embodiment, the gears within the gear mechanism 317 can slide along the longitudinal axis relative to each other. As such, when an axial force is applied to the access assembly 109, the access assembly 109 and gear(s) 317B coupled thereto can slide longitudinally from the distal position to the proximal position. The drive spindle 320 and gear(s) 317A coupled thereto and remain stationary relative to the longitudinal position. The movement of the access assembly 109 and gear(s) 317B can disengage a locking feature, e.g. ratchet teeth 324, 334 and can allow the gear mechanism 317, drive spindle 320 and access assembly 109 to rotate, as described herein. The system 300 can further include an activation spring 390 configured to bias the access assembly 109 and gear(s) 317B towards the distal, locked position. In an embodiment the locking feature can be configured to engage the drive gear 317A coupled with the drive spindle 320.

In an embodiment, a gear ratio between the drive spindle 320 and the access assembly 109 can be greater than 1.0. Further the locking feature can be configured to engage the driven gear 317B coupled to the access assembly 109. Advantageously, the force required by the locking feature to engage and inhibit movement of the driven gear 317B can be less than the force required to engage and inhibit movement of the drive gear 317A where the drive ratio is greater than 1.0.

While some particular embodiments have been disclosed herein, and while the particular embodiments have been disclosed in some detail, it is not the intention for the particular embodiments to limit the scope of the concepts provided herein. Additional adaptations and/or modifications can appear to those of ordinary skill in the art, and, in broader aspects, these adaptations and/or modifications are encompassed as well. Accordingly, departures may be made from the particular embodiments disclosed herein without departing from the scope of the concepts provided herein. 

What is claimed is:
 1. An intraosseous access device, comprising: a housing; a trigger; and a drive train assembly, a portion of the drive train assembly slidably engaged with the housing, and configured to transition between a distal position, and a proximal position that actuates the trigger.
 2. The intraosseous access device according to claim 1, wherein the portion of the drive train assembly slidably engaged with the housing includes one of an electric motor, a gear assembly, a coupling structure, or an access assembly.
 3. The intraosseous access device according to claim 1, wherein the trigger is configured to connect a power supply with the drive train assembly when the trigger is actuated.
 4. The intraosseous access device according to claim 3, wherein the power supply is a battery pack disposed within the housing and configured to be removable and replaceable therefrom and wherein the battery pack is one of rechargeable or non-rechargeable battery pack.
 5. The intraosseous access device according to claim 2, further including one of a force transducer, a variable speed sensor, a battery charge indicator, a timed stop sensor, or a trigger lock.
 6. The intraosseous access device according to claim 5, wherein the variable speed transducer is configured to modify a speed of the electric motor according to the amount of distal driving force applied to the intraosseous access device.
 7. The intraosseous access device according to claim 5, wherein the timed stop sensor is configured to stop the electric motor after a predetermined amount of time has elapsed.
 8. The intraosseous access device according to claim 5, wherein the trigger lock is transitionable between a locked position and an unlocked position, the trigger lock inhibiting the portion of the drive train assembly from transitioning to the proximal position when in the locked position.
 9. The intraosseous access device according to claim 1, further including a biasing member configured to bias the portion of the drive train assembly towards the distal position.
 10. The intraosseous access device according to claim 9, wherein a first force required to deform the biasing member and transition the portion of the drive train assembly from the distal position to the proximal position is greater than a second force required for a needle of an access assembly to penetrate a skin surface and less than a third force required for the needle to penetrate a bone cortex.
 11. The intraosseous access device according to claim 9, further including a tensioning nut configured to adjust a tension of the biasing member.
 12. The intraosseous access device according to claim 9, further including a force indicator configured to indicate an amount of force exerted on the biasing member.
 13. The intraosseous access device according to claim 12, wherein the force indicator includes one of a mechanical slider, a rotational dial, a series of graduated markings, or a series of LED lights.
 14. A method of placing an intraosseous access assembly, comprising: providing an intraosseous access device, comprising: a driver; a drive train assembly, a portion of the drive train assembly transitionable between a first position and a second position; and an access assembly coupled to the drive train and including a needle; providing a first force to urge the access device distally until a tip of the needle penetrates a skin surface and contacts a bone cortex; providing a second force to urge the access device distally and transition the portion of the drive train assembly from a first position to a second position; rotating the access assembly; and drilling the needle through a bone cortex.
 15. The method according to claim 14, wherein the drive train includes one of a power source, an electronic control board, an electric motor, a gear assembly, or a coupling interface.
 16. The method according to claim 15, wherein the power source further includes a replaceable rechargeable battery pack or a replaceable non-rechargeable battery pack.
 17. The method according to claim 14, wherein the drive train includes one of a drive spring, a drive spindle, a locking flange, or a coupling interface.
 18. The method according to claim 14, further including an activation biasing member configured to bias the portion of the drive train assembly towards the first position, and wherein a force required to deform the activation biasing member is greater than the first force and less than second force.
 19. The method according to claim 18, further including a tensioning nut configured to adjust a tension of the activation biasing member.
 20. The method according to claim 15, further including a time out sensor configured to cease rotating the access assembly after a predetermined amount of time has elapsed.
 21. An access device, comprising: a driver housing; a drive spindle configured to rotate axially within the driver housing and configured to transition between a locked position and an unlocked position; a drive spring configured to rotate the drive spindle; and an access assembly coupled to the drive spindle.
 22. The access device according to claim 21, further including an activation biasing member configured bias the drive spindle to the locked position.
 23. The access device according to claim 22, wherein a first force required to deform the activation biasing member and transition the drive spindle from the distal position to the proximal position is greater than a second force required for a needle of the access assembly to penetrate a skin surface and less than a third force required for the needle to penetrate a bone cortex.
 24. The access device according to claim 22, wherein the activation biasing member is a compression spring and the first force is between 2 lbs and 4 lbs of force.
 25. The access device according to claim 22, further including a tensioning nut threadably engaged with the driver housing, and configured to modify an amount of force required to deform the activation biasing member.
 26. The access device according to claim 21, wherein the drive spindle further includes a locking flange configured to engage the driver housing and inhibit axial rotation when the drive spindle is in the locked position.
 27. The access device according to claim 26, wherein the locking flange engages the driver housing with one of a plurality of ratchet teeth, a lug and detent, a frangible bridge, or a locking lever.
 28. The access device according to claim 21, wherein the drive spring includes one of a torsion spring or a flat spring. 